There are various technologies available in the marketplace for an organization to communicate in real-time with its personnel deployed in the field.
At the most basic level, the organization can maintain direct verbal communication using one or more kinds of mobile communication devices, such as cellular phones, two-way radios or other handheld devices. With the necessary wireless data connection, some of those devices can also transmit and receive various data through instant messaging, text messaging, mobile email, multimedia messaging and comparable service offerings. Using multimedia messaging, for instance, the organization and its deployed personnel can share messages with each other that include previously stored data files, such as text, photos, animated graphics, voice messages, and pre-recorded video clips.
The ability to communicate effectively becomes more challenging as the situation in the field becomes more fluid. An incident may have occurred, be in the process of occurring or be at risk of occurring. The more urgent and/or geographically dispersed the incident, the harder it can be for the organization to remotely monitor the situation and provide effective guidance to deployed personnel. Hurricane Katrina provides but one recent example of the communication challenges that can arise. At least in the initial stages of an incident, an organization may be relying on two-way verbal communications with fast-moving personnel on the ground. If the organization wants live visual imagery to help monitor and analyze the situation, it has several potential means to obtain it.
The organization can seek any available satellite imagery or aerial photography of the incident location. These technologies can produce high-resolution images which are increasingly available from public and private sources. For example, the National Oceanic and Atmospheric Administration made available on its Website images of the Gulf coast following Hurricane Katrina (http://ngs.woc.noaa.gov/katrina/). From the organization's perspective, the problem with these technologies is the lag that occurs from the time an incident has first occurred, to the time the satellite or aerial vehicle is physically in a position to capture the imagery (if at all), to the time it takes to process the captured imagery and make it available for viewing. This time lag can be measured in hours, days or longer, depending on various factors.
If the organization has its own video surveillance network in place in the area of interest, it can check whether any of its networked cameras are capturing the requisite imagery. That technology has been evolving over the years. The traditional closed-circuit TV setup involves analog cameras mounted at fixed positions and connected to a central command center via a dedicated cable connection. The cameras capture and transmit complete image frames, which are viewed on a television monitor and archived using a video recording device. If a particular camera has pan-tilt-zoom (PTZ) controls, the command center may also be able to remotely access those controls for enhanced viewing angles.
A recent trend has been the creation of IP-based surveillance networks of fixed cameras connected via wired and/or wireless networks. Such fixed IP cameras capture raw image frames that are compressed prior to transmission using a commercially available compression standard. (Equipment on the network can also convert analog camera frames to digital ones using various commercially available technologies.) Two of the most common compression standards are the Motion JPEG (or M-JPEG) standard and the MPEG standard.
The motion JPEG standard, or Motion Joint Photographic Experts Group standard, compresses each raw image on an intraframe or frame-by-frame basis. The MPEG standard, or Moving Pictures Expert Group standard, compresses the raw images on an intra-frame and inter-frame basis. Once compressed, the imagery is capable of being viewed, analyzed and stored in multiple ways. By way of example, the imagery can be viewed on computer monitors, certain mobile devices, and other equipment, and can be archived on digital video recorders, personal computers, and other mass storage solutions.
An IP-based network can provide other benefits as well. Many fixed IP cameras (and converted analog cameras) have a Web server application embedded in them. Each Web server has a unique URL, or Uniform Resource Locator, which may allow a fixed camera's live image stream to be viewed remotely through any Web browser or other Web-enabled application. The Web browser communicates directly with the fixed camera's dedicated Web server using a common Web protocol such as HTTP (Hypertext Transfer Protocol) or RTP (Real Time Protocol). Various vendors make available software applications that allow a mobile communication device to remotely view a fixed camera's live image stream through the embedded Web browser on the mobile device. Some of those applications also allow the mobile communication device to remotely control a fixed camera's available PTZ movements.
Further, a fixed camera's geospatial coordinates, if available, can be mapped to a Geographic Information System (GIS) or other viewing application for enhanced visualization by an organization. The Google Earth™ viewing application is one increasingly popular example of this type of service offering. Depending on each service offering's particular format, a camera's physical location can be depicted as an icon on a map, and the camera's URL can be shown as a hyperlink. By clicking on the hyperlink, the camera's live image stream can be viewed on the screen using a Web browser connected to the camera's server.
One problem with any analog or IP-based surveillance network is the inherent geographical limits of its fixed network cameras. A video camera has a limited viewing area/range. If an incident is occurring 50 miles from the nearest fixed camera, the organization and its mobile personnel will not be able to view the event. If an organization has the available resources, it can seek to put in place near the incident a temporary surveillance network using cameras that transmit over a wireless network. This type of network is often set up using a Wi-Fi® wireless local area network or in some cases using an available commercial cellular network or a satellite connection.
Even if an organization deploys a temporary mobile network, there are inherent limitations. There will inevitably be an initial time delay in setting up the network, and the network will still not be effective beyond the range of its cameras. There will also be an additional lag each time the network is redeployed to a new location in an effort to keep up with a geographically dispersed incident.
An organization can also seek to obtain visual images and other data from its deployed personnel or other sources near the incident. There are various data distribution technologies available to do so.
There are commercially available videophones and other video conferencing technologies that allow for simultaneous, peer-to-peer video and audio data transmissions, but only among connected users operating compatible viewing hardware.
A person with a digital camera, camcorder, webcam or comparable device can capture live images, transmit them via a wired (or in some cases wireless) connection to a personal computer or a laptop and save them as data files. Those data files can then be transferred through an email-type transfer via a wired or wireless connection. If the person has a media server installed on the personal computer or laptop, the data files can be made available for remote viewing on the media server. Alternatively, the data files can be transferred to a central server that is accessible via a communication network, such as the Internet. That stored data is then available for remote downloading by other registered users using a compatible video player.
If the person has a mobile communication device with an embedded camera, such as a camera-equipped cell phone, that person may be able to capture a still image or a short video clip on the device, save it as a data file and transfer it through an email-type transfer via a wired or wireless connection to one or more cellular numbers or email addresses. The individual can also transmit an accompanying text message or voice recording. Alternatively, there are applications available that allow the mobile communication device to stream live video and/or audio data directly to a central server for remote viewing as well.
In some cases, the ability to “webcast”, “podcast” or use similar technologies allows certain data files to be made available for remote viewing by other users or automatically delivered to another user's computer at prescribed intervals or based on the occurrence of some event.
The preceding data distribution technologies may also allow certain captured data files to be tagged with their corresponding geospatial coordinates for subsequent viewing on a GIS service. Through various available means, the coordinates can be added to a digital image's exchangeable image file format (EXIF)—an industry standard—allowing the image to be displayed as an overlap on a digital map. Some services allow a digital image of any age to be manually dragged to its originating location on a digital map to create the linkage. Google's Picasa™ photo organizer, for instance, offers a tagging service in conjunction with Google Earth™. The tagging can occur through multiple other means as well. The tagging can occur on the device itself, for example, if the device has the necessary Global Positioning System (GPS) chipset or if the device may be communicatively coupled to a separate GPS receiver. The tagging can also be accomplished through the use of digital mapping software applications and other means in which the timestamp of a digital image is matched to the timestamp of the geospatial coordinates captured by the separate GPS receiver.
One disadvantage with data distribution technologies, such as those described above, is that the data flows can be relatively slow and inefficient, particularly during an emergency. With e-mail-type transfers, it can take time to set up the e-mail message, add one or more addressees, add the attachments, and type any accompanying text. With a media server, a remote viewer must know the IP address of the media server, must know the file is available for viewing, and must have access to a compatible media player to view it. Further, the connection might not even be available if the media server is running on hardware that is using a wireless data connection due to the manner in which the commercial cellular networks assign changing IP addresses.
Uploading or streaming data files directly to a central server allows for simultaneous viewing by any number of associated users, but that, by itself, is not conducive to real-time interaction among the organization and its dispersed personnel. The data flow is still passive, as data files are typically deposited in a single location for remote viewing by associated users, who may be required to search, identify, download, and execute applications for displaying or processing the data files. For example, if employee A is streaming live video directly to the server, employees B and C may be required to affirmatively establish independent connections to that server to view the live feed (or the archived feed if employee A has ceased transmitting video at the point employees B and C establish their server connection).
One potential challenge arises when Employee A is streaming live video and wants one or more devices in a heterogeneous network with entirely separately geographical locations (some with fixed computing platforms and some with handhelds and other mobile computing devices) to immediately and automatically display the same live video stream. Another challenge may arise when employee A is watching a live feed from another source (such as a fixed camera) and wants one or more devices to display the live feed. In another example, employee B may be watching a live feed being sent simultaneously (i.e., in real-time) by employee A, and employee B wants to cause the devices associated with employees C and D to display that same live feed as well, without requiring action by employees C and D. In yet another example, an organization (or associated user of an organization's network) may create a new data file or obtain an existing data file—such as a still photo, a map or other data file—and may wish to share the file immediately with other users, without requiring any prior notification to them or any independent action by them. Thus, a dynamic command and control communication system may be required that allows an organization and its employees to acquire and distribute live video, audio, and data streams in real-time and provide a platform for causing one or more devices on the organization's network to automatically display, stream, or process the data, without specific interaction from a user of the device.
Thus, a need exists for a mobile command and control system that can overcome the problems associated with the real time capture and distribution of data files using fixed or mobile computing platforms.